This disclosure relates to composite airfoils, such as blades for gas turbine engines.
Gas turbine engine fan blades have typically been formed from strong and durable metal alloys, such as titanium alloy, to achieve a desired degree of strength and durability under the operating conditions of the engine. More recently, there has been interest in composite blades to reduce weight, for example. A composite blade may include a composite core sandwiched between composite skins. The composite core may include a three-dimensional network of reinforcing fibers in a polymer matrix, and the composite skins typically include unidirectionally oriented fibers in polymer matrices. The composite core provides delamination resistance and the composite skins provide strength and resistance to deformation under the known stresses on the blade during operation of the engine.
One method for fabricating a composite blade includes forming a preform of the composite core that includes the network of fibers in an uncured matrix. The composite skins may be formed from prepreg fiber layers that are arranged on the preform core. The perform core and the prepreg fiber layers are then co-cured to form the blade.